Methods and apparatus for reducing interference in wireless communication systems

ABSTRACT

In accordance with a method for reducing interference in a wireless communication system, information about at least one disallowed beam corresponding to at least one served user may be determined. Scheduling decisions for served users may be made so as to avoid transmissions via the at least one disallowed beam. Data may be transmitted to users in accordance with the scheduling decisions.

TECHNICAL FIELD

The present disclosure relates generally to wireless communicationsystems. More specifically, the present disclosure relates to methodsand apparatus for reducing interference in wireless communicationsystems.

BACKGROUND

Wireless communication devices have become smaller and more powerful inorder to meet consumer needs and to improve portability and convenience.Consumers have become dependent upon wireless communication devices suchas cellular telephones, personal digital assistants (PDAs), laptopcomputers, and the like. Consumers have come to expect reliable service,expanded areas of coverage, and increased functionality. Wirelesscommunication devices may be referred to as mobile stations, stations,access terminals, user terminals, terminals, subscriber units, userequipment, etc.

A wireless communication system may simultaneously support communicationfor multiple wireless communication devices. A wireless communicationdevice may communicate with one or more base stations (which mayalternatively be referred to as access points, Node Bs, etc.) viatransmissions on the uplink and the downlink. The uplink (or reverselink) refers to the communication link from the wireless communicationdevices to the base stations, and the downlink (or forward link) refersto the communication link from the base stations to the wirelesscommunication devices.

Wireless communication systems may be multiple-access systems capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., bandwidth and transmit power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A through 1D illustrate an example showing how served users maybe scheduled so as to avoid the use of disallowed beams;

FIG. 2 illustrates another example showing how served users may bescheduled so as to avoid the use of disallowed beams;

FIGS. 3A through 3C illustrate another example showing how served usersmay be scheduled so as to avoid the use of disallowed beams;

FIG. 4 illustrates another example showing how served users may bescheduled so as to avoid the use of disallowed beams;

FIG. 5 illustrates a system for reducing interference in a wirelesscommunication system;

FIG. 6 illustrates a method for reducing interference in a wirelesscommunication system;

FIG. 7 illustrates means-plus-function blocks corresponding to themethod shown in FIG. 6; and

FIG. 8 illustrates various components that may be utilized in a wirelessdevice.

DETAILED DESCRIPTION

A method for reducing interference in a wireless communication system isdisclosed. In accordance with the method, information about at least onedisallowed beam corresponding to at least one served user may bedetermined. Scheduling decisions for served users may be made so as toavoid transmissions via the at least one disallowed beam. Data may betransmitted to users in accordance with the scheduling decisions.

An apparatus for reducing interference in a wireless communicationsystem is also disclosed. The apparatus includes a processor and memoryin electronic communication with the processor. Instructions may bestored in the memory. The instructions may be executable to determineinformation about at least one disallowed beam corresponding to at leastone served user. The instructions may also be executable to makescheduling decisions for served users so as to avoid transmissions viathe at least one disallowed beam. The instructions may also beexecutable to transmit data to users in accordance with the schedulingdecisions.

An apparatus for reducing interference in a wireless communicationsystem is also disclosed. The apparatus may include means fordetermining information about at least one disallowed beam correspondingto at least one served user. The apparatus may also include means formaking scheduling decisions for served users so as to avoidtransmissions via the at least one disallowed beam. The apparatus mayalso include means for transmitting data to users in accordance with thescheduling decisions.

A computer-program product for reducing interference in a wirelesscommunication system is also disclosed. The computer-program productincludes a computer-readable medium having instructions thereon. Theinstructions may include code for determining information about at leastone disallowed beam corresponding to at least one served user. Theinstructions may also include code for making scheduling decisions forserved users so as to avoid transmissions via the at least onedisallowed beam. The instructions may also include code for transmittingdata to users in accordance with the scheduling decisions.

A wireless communication system may provide communication for a numberof cells, each of which may be serviced by a base station. A basestation may be a fixed station that communicates with access terminals.A base station may alternatively be referred to as an access point, aNode B, or some other terminology.

Access terminals may be fixed (i.e., stationary) or mobile. Accessterminals may alternatively be referred to as user terminals, terminals,subscriber units, remote stations, mobile stations, stations, etc.Access terminals may be wireless devices, cellular phones, personaldigital assistants (PDAs), handheld devices, wireless modems, laptopcomputers, personal computers, etc. A variety of algorithms and methodsmay be used for transmissions in a wireless communication system betweenthe base stations and the access terminals.

A communication link that facilitates transmission from a base stationto an access terminal may be referred to as a forward link, and acommunication link that facilitates transmission from an access terminalto a base station may be referred to as a reverse link. Alternatively, aforward link may be referred to as a downlink or a forward channel, anda reverse link may be referred to as an uplink or a reverse channel.

A cell may be divided into multiple sectors. A sector is a physicalcoverage area within a cell. Base stations within a wirelesscommunication system may utilize antennas that concentrate the flow ofpower within a particular sector of the cell. Such antennas may bereferred to as directional antennas.

A system where one transmitter is used to transmit data to one receivermay be referred to as a SISO (single-input and single-output) system,whereas a system where more than one transmitter is used and more thanone receiver is used may be referred to as a MIMO (multiple-input andmultiple-output) system. MIMO systems may have certain advantages overSISO systems, such as increased data rate and increased receiversensitivity.

OFDM (orthogonal frequency division multiplexing) is a digitalmulti-carrier modulation technique that has recently found wide adoptionin a variety of high-data-rate communication systems. With OFDM, atransmit bit stream may be divided into multiple lower-rate sub-streams.Each sub-stream may be modulated with one of multiple orthogonalsub-carriers and sent over one of a plurality of parallel sub-channels.OFDMA (orthogonal frequency division multiple access) is a multipleaccess technique in which users are assigned sub-carriers in differenttime slots.

Forward link scheduling in a wireless communication system (e.g., acellular network) may be accomplished by having each user feed back itsdesired serving sector and an associated data rate, or channel quality,to the base station. This allows users moving throughout a geographicregion to hand-off between sectors to generally be served by the closesttransmitter, based on selecting the serving sector according to thesignal-to-noise-plus-interference ratio (SINR). In MIMO systems withmultiple transmit and multiple receive antennas, the users may also feedback to their serving sector a desired number of streams (the so-calledrank of the channel) as well as a target combined data rate, or feedback a desired data rate per stream. In systems with multiple potentialspatial beams per sector (sometimes referred to as MIMO preceding) usersmay also feed back to their serving sector the index of the desired beamupon which they want to be served. These techniques correspond tofeeding back side information to the serving sector as a means toachieve better link efficiency from the serving sector to the user.

In accordance with the present disclosure, information about disallowedbeams may be determined and used for purposes of scheduling served userswithin a wireless communication system. A “disallowed beam”corresponding to a particular user refers to a beam that is expected tocause significant interference to the user. In the present disclosure,the term “beam” is used generally and may correspond to any effectiveantenna pattern created by any combination of antenna patterns, elementpatterns, and complex antenna array weight vectors.

Users may determine information about disallowed beam(s) and feed thisinformation back to the appropriate sector(s), which may then use theinformation to make scheduling decisions. For example, if a userdetermines that a beam corresponding to a particular sector (which maybe a neighboring sector or the user's serving sector) is a disallowedbeam, then the user may provide information about the disallowed beam tothe sector. The sector may then attempt to schedule served users in sucha way that transmissions do not occur via the disallowed beam.

In addition to (or possibly instead of) the users themselves determininginformation about disallowed beam(s), base stations may determineinformation about disallowed beam(s) corresponding to served users. Thismay be done in time division duplex (TDD) systems, for example.

With appropriate design and constrained scheduling, the disallowed beamsfor a given user may be avoided in a particular time slot and/or set ofOFDM tones while the user is served on preferred beam(s) from theserving sector to achieve various combinations of SIMO, MIMO and spatialdivision multiple access, or SDMA (i.e., where more than one user isserved simultaneously on the same time slot and tones but on differenttransmit beams). This decreased interference may translate to improvedforward link performance in terms of coverage and/or data rate.

FIGS. 1A through 1D illustrate an example showing how interference canbe mitigated from the transmissions of other sectors in accordance withthe present disclosure. Referring initially to FIG. 1A, it may bedesirable for a first user 104 a to be served via a desired beam 106 afrom its serving sector 102 a. To minimize interference, it may also bedesirable for neighboring sectors 102 b, 102 c to avoid transmission oncertain disallowed beams 106 b, 106 c, 106 d.

Referring now to FIG. 1B, it may be desirable for a second user 104 b tobe served via a desired beam 106 e from its serving sector 102 c. Tominimize interference, it may also be desirable for neighboring sectors102 b, 102 d to avoid transmission on certain disallowed beams 106 c,106 f.

Referring now to FIG. 1C, it may be desirable for a third user 104 c tobe served via a desired beam 106 g from its serving sector. To minimizeinterference, it may also be desirable for a neighboring sector 102 e toavoid transmission on a disallowed beam 106 h.

FIG. 1D illustrates how the three users 104 a, 104 b, 104 c may besimultaneously served via the respective desired beams 106 a, 106 e, 106g from the respective serving sectors 102 a, 102 c, 102 b, whileavoiding the respective disallowed beams 106 b, 106 c, 106 d, 106 f, 106h from the respective neighbor sectors 102 b, 102 c, 102 e.

In the example of FIGS. 1A through 1D, each sector 102 may be selectedas the serving sector 102 by only one user 104 and each sector 102 maybe able to serve on that beam 106 and avoid the disallowed beams 106without explicit coordination with other sectors 102 or cells.

However, when there are large numbers of users per sector and aparticular beam from a sector is selected as the desired serving beamfor a particular user while that beam is selected as being disallowedfor another user in an adjacent sector, then the sectors may coordinatewith one another to accommodate both users (such as serving the twousers on different time slots or tones so that the beam can be used toserve the desired user). This inter-sector coordinated scheduling couldoccur in a centralized location that receives the feedback to makescheduling decisions spanning multiple sectors or cells. In addition (orinstead), there could be communication between cells or sectors to relaypertinent information or scheduling decisions, such as a broadcast tolocal neighbors of a scheduled beam that the sector is going to serve auser on.

Although a user may feed back a serving beam and disallowed beams to thenetwork, the network may not honor the user's requests and those beamsmay end up getting used while the user is being served. For example,quality-of-service (QoS) considerations for delay sensitive applicationsmay cause the network to not obey a user's request to have a neighboringbeam not be used while the user is being served. In addition, a user maybe served on a different beam than the selected serving beam if one ormore other users have indicated that that particular serving beam wasexpected to cause high interference. The result may be that a givensector may obey some, none, or all of the requests from the users in itssector and neighboring sector(s). As such, the amount of coordinatedscheduling and algorithm complexity can be decreased by relaxing theconstraints either on an as needed basis for QoS reasons or due toimplementation complexity considerations.

For simplicity, the scheduling has been described to avoid interferencebased on beam selection that occurs on a particular time slot and/orOFDM tone. In general, the scheduling performed by each sector,coordinated across sectors, or performed globally at a centralizedlocation may also be concerned with the scheduling of users across tonesand/or time slots.

In general, the spatial beams may correspond to either azimuthdirections as depicted in FIGS. 1A through 1D, or more generally to anyspatial beam formed by various combinations of transmit antennas andweights. Such combinations may be achieved based on complex basebandweights being applied to the transmit antennas. For example, a usercould feed back M bits to denote one of 2^(M) different beams. The value2^(M) could be specified upfront based on a particular choice of 2^(M)different weight vectors. The beams may be thought of as columns of amatrix.

The beam selection fed back from a user to the network of one or morebase stations may be in the form of the beam index, which may bereferred to as partial channel state information at the transmitter(partial CSIT). Of course, other methods of communicating the selectionof the serving and disallowed beams are also possible in addition tothose specifically described herein.

The feeding back of all information may not be required in certainsystems, such as those where the network can make measurements on thereverse link that are applicable to the forward link. In a frequencydivision duplex (FDD) network, the base station receivers might only beable to use the reverse link to achieve a coarse measurement to estimatethe forward link beam strength at each user (e.g., based on path loss,shadowing, and/or beam pattern knowledge) but may not necessarily beable to cover the effects of fading due to the frequency separationbetween the forward link and the reverse link. In time division duplex(TDD) applications, however, some base stations could also makemeasurements that would accurately estimate the forward link beamstrengths at various users. In TDD systems, the full channel stateknowledge of complex frequency response can be estimated at thetransmitter (so-called full CSIT) with varying levels of accuracydepending on calibration, signal-to-noise ratio (SNR), Doppler, etc.Therefore, to implement the techniques described herein, not all of theinformation needs to be explicitly fed back from the users to thenetwork.

Regardless of how the information becomes known to the scheduler (e.g.,based on feedback or measurements), the scheduling described herein mayseek to achieve a compromise of using the beams that are best for theserved users but avoiding those beams that cause high interference toother simultaneously (in time/frequency) served users. For example,users could continue to feed back only their desired beam(s) for theirdesired serving sector and the base stations could perform theirscheduling of users onto beams and/or tones and/or time slots based onthe combination of the user feedback of the desired beam and the reverselink-derived estimates of how much interference that would create toother scheduled users. Alternatively, in TDD systems, reverse linkmeasurements could also be used to estimate and select the transmitserving beam(s) to use from the serving sector, while the interferenceavoidance may be made known to the schedulers by users feeding backinformation for the interfering beams to be avoided by the sectors. Forexample, with full CSIT, the sector could transmit to a user along theeigenmodes of the user's channel, or it could choose from a fixed set ofbeams those that are closest to (have the largest inner product with)the eigenmodes, provided those beams do not cause high interference toothers. Within the context of interference avoidance based on knowledgeof disallowed beams, various other forward link linear transmittechniques are possible such as transmitting on a subspace orthogonal tothe disallowed beams.

In general, there may not be any restriction on the number of selecteddesired beams and a user with multiple receiver antennas may communicateto the serving base station feedback to be served on multiple beamssimultaneously (to achieve the degree of freedom gain from spatialmultiplexing MIMO transmission which may be useful at a highsignal-to-noise ratio). For example, users may select one or more beamsupon which to be served from the serving sector and feed back one ormore disallowed beams that the user does not want neighboring sectors touse.

An example is shown in FIG. 2. As shown, a first user 204 a may beserved multiple streams of data simultaneously via the desired beams 206a, 206 i from its serving sector 202 a. To minimize interference withthe first user 204 a, neighbor sectors 202 b, 202 c may avoidtransmission on disallowed beams 206 b, 206 c, 206 d corresponding tothe first user 204 a. Similarly, a second user 204 b may be servedmultiple streams of data simultaneously via the desired beams 206 e, 206j from its serving sector 202 c, and neighbor sectors 202 b, 202 d mayavoid transmission on disallowed beams 206 c, 206 f corresponding to thesecond user 204 b. A third user 204 c may be served a single stream ofdata from the desired beam 206 g of its serving sector 202 b, and aneighbor sector 202 e may avoid transmission on a disallowed beam 206 hcorresponding to the third user 204 c.

There are many different possible MIMO implementations. In accordancewith the present disclosure, any of the various MIMO techniques may becombined with the additional constraint of scheduling to avoiddisallowed beams.

Another potential application is simultaneously serving multiple usersfrom a particular sector. As indicated above, when more than one user isserved simultaneously on the same time slot and tones but on differenttransmit beams, the technique may be referred to as spatial divisionmultiple access (SDMA). In general, in the context of the presentdisclosure, there are no restrictions on the definition of a sector or acell. Although the multiple users 204 being served in FIG. 2 were eachserved by a unique sector 202, users in the same sector may also beserved simultaneously. This may be accomplished by having the users feedback not only their desired beam(s) from the serving sector and theirundesired beams from other sectors, but also the undesired beams fromtheir serving sector.

An example is shown in FIGS. 3A through 3C. Referring initially to FIG.3A, it may be desirable for a first user 304 a to be served via adesired beam 306 a from its serving sector 302 a. To minimizeinterference, it may also be desirable for neighbor sectors 302 b, 302 cto avoid transmission on disallowed beams 306 b, 306 c, 306 d. Inaddition, it may be desirable for the serving sector 302 a to also avoidtransmission on a disallowed beam 306 k.

Referring now to FIG. 3B, it may be desirable for a fourth user 304 d tobe served via a desired beam 306 i from its serving sector 302 a. Tominimize interference, it may be desirable for neighbor sectors 302 c,302 f to avoid transmission on disallowed beams 306 d, 306 l. Inaddition, it may be desirable for the serving sector 302 a to also avoidtransmission on a disallowed beam 306 m.

FIG. 3C shows how the network may attempt to satisfy the constraintsshown in FIG. 3A for the first user 304 a and the constraints shown inFIG. 3B for the fourth user 304 d, while also satisfying constraints fora second user 304 b and a third user 304 c. As shown, the first user 304a may be served via a desired beam 306 a from its serving sector 302 a.Neighbor sectors 302 b, 302 c may avoid transmission on disallowed beams306 b, 306 c, 306 d corresponding to the first user 304 a. In addition,it may be desirable for the serving sector 302 a to also avoidtransmission on a disallowed beam 306 k.

The second user 304 b may be served multiple streams of datasimultaneously via the desired beams 306 e, 306 j from its servingsector 302 c. Neighbor sectors 302 b, 302 d may avoid transmission ondisallowed beams 306 c, 306 f corresponding to the second user 304 b.

The third user 304 c may be served via a desired beam 306 g from itsserving sector 302 b. A neighbor sector 302 e may avoid transmission ona disallowed beam 306 h corresponding to the third user 304 c.

The fourth user 304 d may be served via a desired beam 306 i from itsserving sector 302 a. Neighbor sectors 302 c, 302 f may avoidtransmission on disallowed beams 306 d, 306 l corresponding to thefourth user 304 d. In addition, the serving sector 302 a may avoidtransmission on a disallowed beam 306 m corresponding to the fourth user304 d.

The example of FIGS. 3A through 3C depicts one sector 302 b serving asingle user 304 c (i.e., single stream transmission), one sector 302 cserving two streams to one user 304 b (i.e., spatial multiplexing MIMO)and one sector 302 a serving two users 304 a, 304 d on different beams306 a, 306 i (i.e., SDMA) in addition to the network attempting to avoidusing the disallowed beams 306 b, 306 c, 306 d, 306 f, 306 h, 306 l, 306m corresponding to the various users 304 a, 304 b, 304 c, 304 d. Anycombination of sector transmission techniques is possible.

The above concepts can be further generalized by considering multipleusers in a given sector being served one or more streams at the sametime (i.e., combined SDMA/MIMO). This is shown in the example of FIG. 4.

As shown, the first user 404 a may be served multiple streams of datasimultaneously via the desired beams 406 a, 406 k from its servingsector 402 a. Neighbor sectors 402 b, 402 c may avoid transmission ondisallowed beams 406 b, 406 c, 406 d.

The second user 404 b may be served multiple streams of datasimultaneously via the desired beams 406 e, 406 j from its servingsector 402 c. Neighbor sectors 402 b, 402 d may avoid transmission ondisallowed beams 406 c, 406 f.

The third user 404 c may be served via a desired beam 406 g from itsserving sector 402 b. A neighbor sector 402 e may avoid transmission ona disallowed beam 406 h.

The fourth user 404 d may be served multiple streams of datasimultaneously via the desired beams 406 i, 406 m from its servingsector 402 a. Neighbor sectors 402 c, 402 f may avoid transmission ondisallowed beams 406 d, 406 l.

Thus, in the example of FIG. 4, the first user 404 a and the fourth user404 d are each served more than one stream at the same time from thesame sector 402. In addition, the network scheduling may be coordinatedin an attempt to avoid using beams 406 that cause high interference.

FIG. 5 illustrates a system 500 for reducing interference in a wirelesscommunication system. A user 504 may determine information such as itsdesired serving sector, and/or the desired serving beam 506 a from thedesired serving sector, and/or one or more disallowed beams 506 b, 506 cfrom neighbor sectors and/or the serving sector. This information may bedetermined by making various forward link measurements. As indicatedabove, the desired serving beam 506 a and/or the disallowed beam(s) 506b, 506 c may be determined with respect to a given time slot and/or OFDMtone.

The user 504 may notify a scheduler 534 a for the desired serving sectorabout the desired serving beam 506 a, and also about the disallowedbeam(s) 506 b from the desired serving sector. The user 504 may alsonotify a scheduler 534 b for the neighboring sector about any disallowedbeam(s) 506 c from the neighboring sector.

In addition to the user 504 determining information about disallowedbeam(s) 506 b, 506 c, the network may also determine information aboutdisallowed beam(s) 506 d, 506 e corresponding to the user 504. This maybe done by making reverse link measurements. Reverse link measurementcomponents 538 a, 538 b are shown for providing this functionality. Thescheduler 534 b for the neighboring sector may be notified about anydisallowed beam(s) 506 d corresponding to the user 504 that aredetermined by making reverse link measurements. Similarly, the scheduler534 a for the desired serving sector may also be notified about anydisallowed beam(s) 506 e corresponding to the user 504 that aredetermined by making reverse link measurements.

The schedulers 534 a, 534 b may determine the scheduling of served usersand beams so as to avoid using the disallowed beams 506 b, 506 c, 506 d,506 e when possible. The schedulers 534 a, 534 b may implement anycombination of SIMO, MIMO, and SDMA transmissions. As shown,communication between the schedulers 534 a, 534 b may occur in order tocoordinate the scheduling of served users.

The schedulers 534 a, 534 b and the reverse link measurement components538 a, 538 b may be implemented in various network entities, such as oneor more base stations. For example, the schedulers 534 a, 534 b and thereverse link measurement components 538 a, 538 b may be implemented atdifferent base stations. Alternatively, the schedulers 534 a, 534 b andthe reverse link measurement components 538 a, 538 b may be implementedat the same base station. This may occur, for example, where the samebase station serves both the desired serving sector and the neighboringsector. Also, although two schedulers 534 a, 534 b are shown in FIG. 5(one for the desired serving sector, and one for a neighboring sector),one scheduler (e.g., a centralized scheduler) may handle the schedulingfor multiple sectors.

FIG. 6 illustrates a method 600 for reducing interference in a wirelesscommunication system. In accordance with the method 600, accessterminals (users) may make 604 forward link measurements to determineinformation such as a desired serving sector, and/or a desired servingbeam from the desired serving sector, and/or one or more disallowedbeams from neighboring sectors and/or the serving sector. Accessterminals (users) may feed back 606 this information to the appropriatenetwork entities (e.g., scheduler(s) at the base station(s)).

If reverse-link activated scheduling has been activated 608, thenreverse link measurements may be made 610 to determine information thatis similar to the information described above. More specifically, foreach user the following may be determined: the desired serving sectorfor the user, and/or the desired serving beam from the desired servingsector, and/or one or more disallowed beams from neighbor sectors and/orthe serving sector. This information may be determined by basestation(s) corresponding to the desired serving sector and/orneighboring sector(s).

One or more schedulers may determine 612 the scheduling of served usersand beams to accomplish any combination of MIMO and SDMA transmissions.This may be done with respect to a given time slot and/or a given set ofOFDM tones. Scheduler(s) may make scheduling decisions so as to avoiddisallowed beam directions when possible. Data may then be transmitted614 to users in accordance with the scheduling decisions that are madeby the scheduler(s). Then, the method 600 may involve moving 616 to thenext time slot and repeating the operations described above.

The method 600 of FIG. 6 may be performed by various hardware and/orsoftware component(s) and/or module(s) corresponding to themeans-plus-function blocks 700 illustrated in FIG. 7. In other words,blocks 604 through 616 illustrated in FIG. 6 correspond tomeans-plus-function blocks 704 through 716 illustrated in FIG. 7.

FIG. 8 illustrates various components that may be utilized in a wirelessdevice 802. The wireless device 802 is an example of a device that maybe configured to implement the various methods described herein.

The wireless device 802 may include a processor 804 which controlsoperation of the wireless device 802. The processor 804 may also bereferred to as a central processing unit (CPU). Memory 806, which mayinclude both read-only memory (ROM) and random access memory (RAM),provides instructions and data to the processor 804. A portion of thememory 806 may also include non-volatile random access memory (NVRAM).The processor 804 typically performs logical and arithmetic operationsbased on program instructions stored within the memory 806. Theinstructions in the memory 806 may be executable to implement themethods described herein.

The wireless device 802 may also include a housing 808 that may includea transmitter 810 and a receiver 812 to allow transmission and receptionof data between the wireless device 802 and a remote location. Thetransmitter 810 and receiver 812 may be combined into a transceiver 814.An antenna 816 may be attached to the housing 808 and electricallycoupled to the transceiver 814. The wireless device 802 may also include(not shown) multiple transmitters, multiple receivers, multipletransceivers and/or multiple antenna.

The wireless device 802 may also include a signal detector 818 that maybe used to detect and quantify the level of signals received by thetransceiver 814. The signal detector 818 may detect such signals astotal energy, pilot energy per pseudonoise (PN) chips, power spectraldensity, and other signals. The wireless device 802 may also include adigital signal processor (DSP) 820 for use in processing signals.

The various components of the wireless device 802 may be coupledtogether by a bus system 822 which may include a power bus, a controlsignal bus, and a status signal bus in addition to a data bus. However,for the sake of clarity, the various busses are illustrated in FIG. 8 asthe bus system 822.

As used herein, the term “determining” encompasses a wide variety ofactions and, therefore, “determining” can include calculating,computing, processing, deriving, investigating, looking up (e.g.,looking up in a table, a database or another data structure),ascertaining and the like. Also, “determining” can include receiving(e.g., receiving information), accessing (e.g., accessing data in amemory) and the like. Also, “determining” can include resolving,selecting, choosing, establishing and the like.

The phrase “based on” does not mean “based only on,” unless expresslyspecified otherwise. In other words, the phrase “based on” describesboth “based only on” and “based at least on.”

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array signal (FPGA) or other programmable logicdevice, discrete gate or transistor logic, discrete hardware componentsor any combination thereof designed to perform the functions describedherein. A general purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core or any other suchconfiguration.

The steps of a method or algorithm described in connection with thepresent disclosure may be embodied directly in hardware, in a softwaremodule executed by a processor or in a combination of the two. Asoftware module may reside in any form of storage medium that is knownin the art. Some examples of storage media that may be used include RAMmemory, flash memory, ROM memory, EPROM memory, EEPROM memory,registers, a hard disk, a removable disk, a CD-ROM and so forth. Asoftware module may comprise a single instruction, or many instructions,and may be distributed over several different code segments, amongdifferent programs and across multiple storage media. A storage mediummay be coupled to a processor such that the processor can readinformation from, and write information to, the storage medium. In thealternative, the storage medium may be integral to the processor.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

The functions described may be implemented in hardware, software,firmware, or any combination thereof. If implemented in software, thefunctions may be stored as one or more instructions on acomputer-readable medium. A computer-readable medium may be anyavailable medium that can be accessed by a computer. By way of example,and not limitation, a computer-readable medium may comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that can be used tocarry or store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Disk and disc, asused herein, includes compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers.

Software or instructions may also be transmitted over a transmissionmedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition oftransmission medium.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein, suchas those illustrated by FIG. 6, can be downloaded and/or otherwiseobtained by a mobile device and/or base station as applicable. Forexample, such a device can be coupled to a server to facilitate thetransfer of means for performing the methods described herein.Alternatively, various methods described herein can be provided via astorage means (e.g., random access memory (RAM), read only memory (ROM),a physical storage medium such as a compact disc (CD) or floppy disk,etc.), such that a mobile device and/or base station can obtain thevarious methods upon coupling or providing the storage means to thedevice. Moreover, any other suitable technique for providing the methodsand techniques described herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the systems, methods, and apparatus described herein withoutdeparting from the scope of the claims.

What is claimed is:
 1. A method for reducing interference in a wirelesscommunication system, the method comprising: determining informationabout at least one disallowed beam corresponding to at least one antennapattern of at least one served user, wherein determining the informationabout the at least one disallowed beam includes: making a measurement ofat least one reverse link from the at least one served user to at leastone base station, wherein the measurement of the at least one reverselink includes partial channel state information at a transmitter; andmaking forward link measurements from a neighboring sector or a servingsector, wherein the forward link measurements correspond to one or moreof a desired serving sector, a desired serving beam, a disallowed beam,downlink or forward channel information, an estimate of forward linkinformation based on the measurement made of the at least one reverselink, and one or more combinations of any of the proceeding; makingscheduling decisions, based at least in part on the measurement made ofthe at least one reverse link and the forward link measurements, forserved users so as to avoid transmissions via the at least onedisallowed beam, wherein the scheduling decisions are coordinatedbetween multiple sectors when the at least one disallowed beam is adesired serving beam for a second user and the scheduling decisions aremade to accommodate the at least one served user and the second user;and transmitting data to users in accordance with the schedulingdecisions.
 2. The method of claim 1, wherein determining the informationabout the at least one disallowed beam comprises receiving theinformation from the at least one served user.
 3. The method of claim 1,wherein transmitting the data in accordance with the schedulingdecisions implements single-input and multiple-output (SIMO)transmissions.
 4. The method of claim 1, wherein transmitting the datain accordance with the scheduling decisions implements multiple-inputand multiple-output (MIMO) transmissions.
 5. The method of claim 1,wherein transmitting the data in accordance with the schedulingdecisions implements spatial division multiple access (SDMA)transmissions.
 6. The method of claim 1, wherein the at least onedisallowed beam corresponds to a neighboring sector of the at least oneserved user.
 7. The method of claim 1, wherein the at least onedisallowed beam corresponds to a serving sector of the at least oneserved user.
 8. An apparatus for reducing interference in a wirelesscommunication system, the apparatus comprising: a processor; memoryaccessible by the processor; instructions stored in the memory, theinstructions being executable to: determine information about at leastone disallowed beam corresponding to at least one antenna pattern of atleast one served user, wherein the instructions to determine theinformation about the at least one disallowed beam include instructionsexecutable to make: a measurement of at least one reverse link from theat least one served user to at least one base station, wherein themeasurement of the at least one reverse link includes partial channelstate information at a transmitter; and forward link measurements from aneighboring sector or a serving sector, wherein the forward linkmeasurements correspond to one or more of a desired serving sector, adesired serving beam, a disallowed beam, downlink or forward channelinformation, an estimate of forward link information based on themeasurement made of the at least one reverse link, and one or morecombinations of any of the proceeding; make scheduling decisions, basedat least in part on the measurement made of the at least one reverselink and the forward link measurements, for served users so as to avoidtransmissions via the at least one disallowed beam, wherein thescheduling decisions are coordinated between multiple sectors when theat least one disallowed beam is a desired serving beam for a second userand the scheduling decisions are made to accommodate the at least oneserved user and the second user; and transmit data to users inaccordance with the scheduling decisions.
 9. The apparatus of claim 8,wherein determining the information about the at least one disallowedbeam comprises receiving the information from the at least one serveduser.
 10. The apparatus of claim 8, wherein transmitting the data inaccordance with the scheduling decisions implements single-input andmultiple-output (SIMO) transmissions.
 11. The apparatus of claim 8,wherein transmitting the data in accordance with the schedulingdecisions implements multiple-input and multiple-output (MIMO)transmissions.
 12. The apparatus of claim 8, wherein transmitting thedata in accordance with the scheduling decisions implements spatialdivision multiple access (SDMA) transmissions.
 13. The apparatus ofclaim 8, wherein the at least one disallowed beam corresponds to aneighboring sector of the at least one served user.
 14. The apparatus ofclaim 8, wherein the at least one disallowed beam corresponds to aserving sector of the at least one served user.
 15. An apparatus forreducing interference in a wireless communication system, the apparatuscomprising: means for determining information about at least onedisallowed beam corresponding to at least one antenna pattern of atleast one served user, the means for determining the information aboutthe at least one disallowed beam using a processor or a processingcircuit and including means for: making a measurement of at least onereverse link from the at least one served user to at least one basestation, wherein the measurement of the at least one reverse linkincludes partial channel state information at a transmitter; and makingforward link measurements from a neighboring sector or a serving sector,wherein the forward link measurements correspond to one or more of adesired serving sector, a desired serving beam, a disallowed beam,downlink or forward channel information, an estimate of forward linkinformation based on the measurement made of the at least one reverselink, and one or more combinations of any of the proceeding; means formaking scheduling decisions using a processor or a processing circuit,based at least in part on the measurement made of the at least onereverse link and the forward link measurements, for served users so asto avoid transmissions via the at least one disallowed beam, wherein thescheduling decisions are coordinated between multiple sectors when theat least one disallowed beam is a desired serving beam for a second userand the scheduling decisions are made to accommodate the at least oneserved user and the second user; and means for transmitting data tousers in accordance with the scheduling decisions.
 16. The apparatus ofclaim 15, wherein determining the information about the at least onedisallowed beam comprises receiving the information from the at leastone served user.
 17. The apparatus of claim 15, wherein transmitting thedata in accordance with the scheduling decisions implements single-inputand multiple-output (SIMO) transmissions.
 18. The apparatus of claim 15,wherein transmitting the data in accordance with the schedulingdecisions implements multiple-input and multiple-output (MIMO)transmissions.
 19. The apparatus of claim 15, wherein transmitting thedata in accordance with the scheduling decisions implements spatialdivision multiple access (SDMA) transmissions.
 20. The apparatus ofclaim 15, wherein the at least one disallowed beam corresponds to aneighboring sector of the at least one served user.
 21. The apparatus ofclaim 15, wherein the at least one disallowed beam corresponds to aserving sector of the at least one served user.
 22. A non-transitorycomputer-readable medium comprising instructions for reducinginterference in a wireless communication system, which when executed bya processor cause the processor to perform operations comprising:determining information about at least one disallowed beam correspondingto at least one antenna pattern of at least one served user, including:making a measurement of at least one reverse link from the at least oneserved user to at least one base station, wherein the measurement of theat least one reverse link includes partial channel state information ata transmitter; and making forward link measurements from a neighboringsector or a serving sector, wherein the forward link measurementscorrespond to one or more of a desired serving sector, a desired servingbeam, a disallowed beam, downlink or forward channel information, anestimate of forward link information based on the measurement made ofthe at least one reverse link, and one or more combinations of any ofthe proceeding; making scheduling decisions, based at least in part onthe measurement made of the at least one reverse link and the forwardlink measurements, for served users so as to avoid transmissions via theat least one disallowed beam, wherein the scheduling decisions arecoordinated between multiple sectors when the at least one disallowedbeam is a desired serving beam for a second user and the schedulingdecisions are made to accommodate the at least one served user and thesecond user; and transmitting data to users in accordance with thescheduling decisions.
 23. The non-transitory computer-readable medium ofclaim 22, wherein determining the information about the at least onedisallowed beam comprises receiving the information from the at leastone served user.
 24. The non-transitory computer-readable medium ofclaim 23, wherein transmitting the data in accordance with thescheduling decisions implements single-input and multiple-output (SIMO)transmissions.
 25. The non-transitory computer-readable medium of claim22, wherein transmitting the data in accordance with the schedulingdecisions implements multiple-input and multiple-output (MIMO)transmissions.
 26. The non-transitory computer-readable medium of claim22, wherein transmitting the data in accordance with the schedulingdecisions implements spatial division multiple access (SDMA)transmissions.
 27. The non-transitory computer-readable medium of claim22, wherein the at least one disallowed beam corresponds to aneighboring sector of the at least one served user.
 28. Thenon-transitory computer-readable medium of claim 22, wherein the atleast one disallowed beam corresponds to a serving sector of the atleast one served user.